1. FIELD OF THE INVENTION
This invention relates generally to automated machine tools programmable to perform multiple machining functions on a workpiece, and more particularly to automated machine tools having a rotary indexing table for rotating the workpiece 360.degree..
2. DESCRIPTION OF THE PRIOR ART
Automated machine tools are wellknown in the art that perform a variety of cutting functions such as milling, drilling, threading, tapping, etc. on a workpiece. These machines are normally provided with a tool carrousel that has numerous cutting tools mounted thereon for performing the variety of functions of the machine. The tool holder is generally a rotatable tool spindle mounted in a drill head adjustably mounted on a vertical column or quill for vertical movement thereon. The tool spindle is mounted for rotation relative to the quill and is moveable axially with respect to the drill head. Additionally, the workpiece is secured to a worktable that is moveable in a x-y horizontal plane for providing a variety of positions to perform the various cutting operations.
The machining operation is performed by the rotatable tool spindle rotatably mounted in a spindle head and arranged to be shifted vertically with respect to the workpiece. Precision cutting is performed, such that a hole center may be precisely located with respect to the axis of the rotatable tool spindle and the combined movement of the worktable in its horizontal plane of movement. During the machining operation, the spindle is rotated at a pre-selected cutting speed and is fed downwardly by the drill head on the quill at a predetermined feed rate. The cutting tool is removably mounted in a chuck of a design wellknown in the art, which is carried by the lower end of the rotatable tool spindle and which forms a part thereon. Additionally, a tool changer is adapted to remove the used tool from the chuck at the end of a cutting operation and replace the used tool with a pre-selected new tool in an automatic manner that eliminates lost time associated with manual tool changing operations.
All these functions are carried out in rapid efficient manner in order to bring about the most efficient operation of the machine tool. The automatic control of the machine tool is provided by a numerical control system operated under the control of a punch tape or other memory device which regulates the table so as to locate a cutting center with respect to the axis of the tool, the automatic selection of the spindle speed, the spindle feed rate on the quill, and other machine functions.
In addition to these operations, it would be desirable if an automated machine tool had the capability to rotate the workpiece on the moveable worktable to efficiently perform continuous machining operations on the workpiece without manually changing the orientation of the workpiece on the moveable worktable.
SUMMARY OF THE INVENTION
There is provided by this invention an automated machine tool having a rotary indexing table that allows a workpiece to be rotated on the worktable to perform continuous machining operation eliminating the need for manual operation to change the orientation of the workpiece on the machine tool. The rotary indexing table has an aperture therein designed to accommodate an indexing tool supported in a rotatable spindle such that with appropriate movements of the moveable worktable the indexing tool causes rotation of the rotary indexing table to a precise position.